DE2427953A1 - METHOD OF MANUFACTURING A VINYL CHLORIDE POLYMER - Google Patents

Description

p 23 5 ^ 3 Dr.K.
Case: Py 26189/26733

IMPERIAL- CHSI-IICAL INDUSTHIES LIMITED, London / Great Britain

METHOD OF MANUFACTURING SIFES VINYL CHLORIDE POLYMER

Priority: June 5, 1973 and January 23, 1974 Ko. 27 331/73 No. 3118/74

The invention relates to the polymerization of vinyl chloride and, more particularly, to a process for Manufacture of vinyl chloride polymers suitable for making pastes.

It started out that vinyl chloride polymers can be produced by a Can produce method in which a dispersion of vinyl chloride or of vinyl chloride and one therewith mixed polymerizable lionomer in the presence of a

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surface-active agent is homogenized by subjecting it to violent shear conditions, for example in a colloid mill _T, a high-performance pump or an ultrasound device, after which the homogenized dispersion obtained is then polymerized in a stirred autoclave using a monomer-soluble initiator.

The vinyl chloride polymers made by this process consist of very small particles (usually in the range 0.1 to 2 ~ u), "which are found in plasticizers dispersed to produce relatively stable dispersions known as "pastes". These are useful in a number of applications such as 3. in molding processes, e.g. open casting, Hotation pouring, slush molding, compression molding and injection molding, or in the coating process, for example by dipping, spraying or brushing techniques, or in the production of "foams.

The particle size distributions of the using a such homogenized dispersion produced vinyl chloride polymers are such that pastes made with the polymer have particularly advantageous properties, such as a low initial viscosity and a slow viscosity increase during aging.

The "homogenized dispersion technique" suffers, however with the disadvantage that homogenization (1) involves the use of expensive, sometimes extensive, homogenization equipment requires, the available homogenization capacity being that polymerizable using this technique Kenge Hönomer limits, and (2) the cycle time for.

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vinyl chloride polymerization increases, resulting in decreased productivity. It now became a process found by which these disadvantages considerably reduced can be.

The invention therefore relates to a process for the production of a vinyl chloride polymer in which vinyl chloride or vinyl chloride is polymerized with up to 30% by weight, based on this, at least one further ethylenically unsaturated monomer which is copolymerizable therewith, the characteristic being that Before the start of the polymerization, a mixture of monomeric material to be polymerized and water, which contains part of the total monomeric material to be polymerized, is homogenized in the presence of an emulsifier and / or a suspending agent and a monomer-soluble polymer initiator and mixed with the remaining part of the polymer to be used in the polymerization / terminating monomeric material, the combined parts then being polymerized to form the vinyl chloride polymer.

Thus, in the process according to the invention, only part of the monomer to be polymerized undergoes homogenization subjected, whereas so far the whole to be polymerized Konomer was used in the homogenization. Despite the homogenization of only part of the monomer feed the vinyl chloride polymer obtained is surprisingly suitable as a paste-forming material in the above-mentioned applications, being in particular an acceptably low one Initial viscosity and viscosity increase rate exhibits upon aging.

So it can be seen that the method according to the invention a shorter cycle time is permitted per reaction batch because namely, the time required for the homogenization is much shorter, since not all of the time to be polymerized Batch of monomer must be subjected to homogenization.

In those cases where a homogenizer is used for the manufacture a homogenized batch is used for a number of reactors, allows the inventive ■ Procedure, a reduction in the cycle time also through other measures, because namely the time during which the Eomogenizer is needed for a "specific reactor, is decreased. In this way the time can be reduced or even switched off during a reactor comes to a standstill, for example by reducing the time it takes to carry out the polymerization / film removal / reactor cleaning3 sequence is required.

Finally, the method according to the invention allows the use of an eomogenization device with a smaller one Capacity and / or the use of fewer homogenizers for a given number of reactors.

It should be pointed out that in the process of the invention the homogenization of the material is so careful and should be carried out as effectively as possible, that is, that it is desired that every part of the homo-geniry no intended batch should in fact be homogenized in a clean and güch-like manner. If on it If this is not observed, then the presence of an unhosiogenized charge can result in a polymer charge which has an unacceptable particle size distribution, i.e. it is a pebble-like product

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and / or revealing deposits; or even completely rt is.

The possibility of an ineffective homogenization is given because of the so-called "set time" of the homogenization 3 stage, which means the general time. during which the batch to be homogenized passes through the homogenizer and during which the homogenizer is "adjusted" in such a way that it results in the desired homogenizing force (when using a high-performance lamp as the homogenizer, the different bridges are set in the various stages the pump). It is clear that during the binstellaeit before the correct. Homogenization The material coming to the homogenizer is either not homogenized at all or is poorly homogenized. Use these difficulties to avoid these problems. The 1-material emerging at the beginning is returned to the etching material which enters the heat generator.

You zxit ¥ elimination of a useless one. The recovery period required for the product depends on the size of the batch to be homogenized. In each case a relatively small one. Charge as wärd used in a liaboranlage .or in on the one pilot plant, for example, _s braticht the Hückführungszeit not be very long, because the opportunities as £ each "ecause of unhomogenized or bad * homogenized Katerials passes quickly once through the homogenizer, because the smallness of the batch are very high. In a technical plant, however, where a much larger batch is to be homogenized, the chances are that the i & l emerging at the beginning will pass through && n.

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Needs so much that it takes longer to drive; is required.

It is not possible to determine the exact time required to indicate, as this depends, among other things, on the respective homogenization device, the "for the homogenization device in question applied eomogenization power and, as mentioned above, depends on the size of the batch to be tosogenized. In practice it should the necessary hindesfcracking time experimentally for a given polymerisation system can be determined, while the return time is changed until reproducible products with an acceptable particle size can be obtained «

JLuBercLaiE it is possible to th close to the natural sheep _t of a polymer which has been obtained by homogenizing the entire Eonanereharge, zoom elaborate by the Mick execution time is changed in a particular system steps until the best approximation obtained.

In order to achieve an economically significant improvement according to the method according to the invention, it is best not to homogenize more than 90% by weight of the material to be polymerized as a whole. Rairde found that an extremely small fraction of the total amount of monomeric material to be polymerized was highly refined; are ksnn, "without the Sigenschaxten of the resulting polymer impaired werden- lter lower Äreszrcert to be homogenized fraction of the initiator in the Honomer is limited only by the solubility of certain So it is Eiöglch that only 3 wt" -% of the at polyaerisierenden

entire monomeric T-üateri & ls are homogenized (where which reads after the homogenization added v / M) without the polyamide properties being impaired.

^s i är practical purposes, however, it is preferred, at least, usually 6 to 75 ■ »preferably 15 to GG% and in particular 25 to 50% of the monomeric material to be polymerized to homogenize% G%.

In the "method according to the invention, it is advantageous to homogenize only part of the water to be used in the polymerization - (the unhomogenized Water and the unhomogenized monomer are added after the homogenization). Through this the above-mentioned economic benefits can be increased.

In such cases, it is best not to homogenize more than 90% by weight of the total amount of water to be used for the polymerization. Again, it is possible to homogenize much less water, ϋε was found that only 10 percent -.% Of the total, are homogenized in the polymerization to use water charge (the best is added after the homogenization) without the polymer properties to suffer .

For practical purposes, however, it is preferred in such cases to homogenize at least 20%, usually 20 to 75%, preferably 2 5 to 60 % and in particular 30 to 50 % of the total water charge.

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It is of course also possible to use the inventive To carry out the method by having a portion of the monomeric material to be polymerized and the total amount of water to be used in the polymerization is homogenized.

A portion of the emulsifier and / or suspending agent that is used or GjH during the polymerization can be used for inhomogenized fraction are added. Alternatively becomes the total amount of emulsifier and / or suspending agent which is used during the polymerization is added to the homogenized fraction. Preferably should be the entire monomer-soluble initiator, which at used for polymerization, incorporated into the homogenized fraction to avoid the possibility of that a coarse product is obtained ..

Any emulsifier or any suspending agent can be used for the process according to the invention. The emulsifier can be anionic, cationic or non-ionic IT ·: ·, door. However, it is preferred to use anionic emulsifiers because they are more effective in stabilizing the resulting polymer latex. Examples of anionic gowns are the sodium salts of sulphated and sulphonated hydrocarbons and fatty acids, such as dioctyl sodium sulphosuccinate, sulphonated diesel oil and sodium lauryl sulphate as well as the salts of alkyl aryl sulphates such as e.g. B: - trium-dodecyl-benzene-sulfonate.

Suspending agents that can be used are protective colloids, such as cellulose derivatives and partially

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_ 9 hydrolyzed Polyvinyl acetates.

It can be any monomer-soluble which generates free radicals Initiator or initiator mixture are used in the process according to the invention »Suitable initiators are Acyl peroxides such as' Lauroyl peroxide and acetyl-cyclohexyl-sulfonyl-peroxide, and Azo compounds such as azodiisobutyronitrile. Dialkyl peroxydicarbonates can also be used as described in GB-PS 978,875 whose relevant information is to be considered included in the present application.

In the method according to the invention, the homogenization can be carried out by any suitable device, such as they were mentioned above. It was found that the homogenization the easiest way to carry out and control it is by using a high-performance pump •can be. A two-stage pump gives very good results. ·

For the production of the homogenized dispersion according to the invention Process can, for example, be a stirred premix of the monomer to be homogenized, V / water, emulsifier or suspending agent and initiator are prepared in a premix container, whereupon the suspension obtained through the homogenizer (if necessary after suitable recycling) and finally into the Reactor is performed. ·

Since the homogenized dispersion should contain at least part of the polymerization initiator, the Homogenization is usually carried out at a temperature at which polymerization takes place. In general

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we mean the homogenization in a suitable manner "at about Hc-ambient temperature or something above, for example 10 to 20 ° C. The polymerization is usually at a "temperature between 40 and 70 ° C, in particular between 50 and 65 ° C, carried out «The selection of the polymerization temperature is largely determined by the The required mechanical properties of the resulting polymer are determined.

After completion of the polymerization, the polymer can from Water can be removed by any suitable drying technique, such as drying on trays, drying, in drums or spray drying.

The invention is illustrated in more detail by the following examples. In the examples, all parts and percentages are expressed by weight.

Example 1 is a comparative example in which the total amounts of monomeric material and water that used in the polymerization, are homogenized.

Examples 2 and 3 demonstrate the invention Process in which a part (50% or 25%) of the polymer to be monomeric Ifeterials is homogenized, the total amount of the in the polymerization to using water is homogenized and all of the emulsifier used in the polymerization in the homogenized fraction is incorporated.

Examples 4 and 5 show the process according to the invention

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in the manner of Examples 2 and 3, but only part of the emulsifier used (50% or 25 ^c / o) is incorporated into the homogenized fraction.

Examples 6 and 7 show the process according to the invention, one TeEL (50% or 12.5%) cLes monomers Ifeterials, a portion (50% or 12.5%) of the water and a part (50 or 12.5% respectively) of the emulsifier of the homogenization be subjected.

In the example S is a part (25%) of the monomer to be polymerized is homogenized · the ilaterials and a portion (25 7 °) of the total Vasaermenge used homogenized, v, is incorporated obei DER entire emulsifier into the homogenized batch.

Example S ict a comparison showing the manufacture of a Vinyl chloride / Yinylacetat-Kischpolyiaers concerns, whereby The parameters to be used in the polymerization C.20. inonosein material and water are homogenized.

Example 10 also relates to the preparation of one Vinyl chloride / vinyl acetate mixed polymer and shows one embodiment of the method according to the invention, wherein only one tea (50%) of the vinyl chloride to be polymerized and only part (50%) of the water is homogenized and all of the vinyl acetate and all of it Emulsifier can be incorporated into the homogenized batch.

BSISFISL 1

50 kg water, 40 kg vinyl chloride, 400 g sodium dodecylbenzoi sulfonate, 80 g lauroyl peroxide and 20 g dicetyl

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peroxydicarbonate were placed in a stainless steel container Steel introduced, from which most of the atmospheric oxygen by evacuation and Purging with nitrogen had been removed. The mixture was stirred for 15 minutes, a coarse dispersion of the Vinyl chloride in water. The mixture was then (after a return time of 5 min) rotating a two-stage high-performance pump homogenizer passed through, the pressure in the first stage being 210 kg / cm ^ and in the second stage 35 kg / cm ^. The homogenized mixture was introduced into a stirred evacuated reaction vessel.

The reaction vessel was heated to 50 ° C. with stirring heated, and this temperature was kept constant for the duration of the reaction. After 9 hours started the pressure in the reaction vessel to drop ', and after a further three hours of polymerization, the Residual pressure released.

The product was in the form of a polymer latex which was dried by spray drying. 100 parts of the dry powder were mixed with 66 parts' dialphanyl phthalate mixed, being a paste with the following viscosity properties was obtained:

Initial viscosity '19 poise Viscosity after 14 days of storage at 25 ° C 38 poise

These viscosity properties are for a paste polymer acceptable.

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EXAMPLE 2

50 kg water, 20 kg vinyl chloride, 400 g sodium dodecylbenzene sulfonate, 80 g lauroyl peroxide and 20 g dicetyl peroxydicarbonate were placed in a stainless steel container, from which most of the atmospheric Oxygen had been removed by evacuating and purging with nitrogen. The mixture was stirred for 15 min. to produce a coarse dispersion of vinyl chloride in water. The mixture was then passed through a two-stage high-performance pump homogenizer (5 min return time) passed through, the pressure in the first stage

ζ- ρ

210 kg / cm "'and in the second stage 35 kg / cm".

The homogenized mixture became a stirred reaction vessel from which most of the nitrogen had been removed and in which '(after removal of oxygen) 20 kg of vinyl chloride had previously been entered. The polymerization was then carried out as in Example 1 carried out at 50 ° C. The time to start the pressure drop was 8 hours.

The product; had the 5 'orm of a latex, and was injection-dried The viscosity characteristics of the polymer were prepared in the same manner as in B _e ispiel 1 determines you waren'wie follows:...'

Initial viscosity. 20 poise

Viscosity after 14 days

Storage at 23 ° C 55 poise

The viscosity properties were for a paetenpolymer acceptable.

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EXAMPLE 5

The procedure of Example 2 was repeated except that the charge to the stainless steel container consists of 50 kg of water ", 10 kg of vinyl chloride, 400 g of sodium dodecyl bensol sulfonate, 80 g lauroyl peroxide and 20 g dicetyl peroxydicarbonate existed and the reactor previously contained 30 kg of vinyl chloride.

The time until the onset of the pressure drop during the polymerization was 9 hours.

The viscosity properties of the polymer were as follows:

Initial viscosity:

Viscosity after storage for 14 days at 2 ° C

24 poise

43 poise

EXAMPLE 4

The procedure of Example 2 was repeated except that the charge to the stainless steel container consists of 50 kg of water, 20 kg of vinyl chloride, 200 g of sodium aodecyl benzene sulfonate, 80 g lauroyl peroxide and 20 g dieetyl peroxydicarbonate existed and the reactor before 2GO g sodium dodecyl benzene sulfonate (as aqueous Solution) and 20 kg of vinyl chloride. The time until the beginning of the pressure drop during the polymerization was 9 hours.

The viscosity properties of the polymer were as follows:

Initially vi sko si t ät

Viscosity after storage for 14 days at 23 ° C

19 poise 35 poise

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EXAMPLE 5

The procedure of Example 2 was repeated except that the charge to the stainless steel vessel was removed from 50 kg of water, 10 kg of vinyl chloride, 100 g of sodium dodecyl benzene sulfonate, 80 g of lauroyl peroxide and 20 g of dicetyl peroxydicarbonate existed and the Eeaktor previously 30 kg of vinyl chloride and 300 g of sodium dodecylbenzene sulfonate (as an aqueous solution).

The time to start the pressure drop during the polymerization was 11 hours.

The viscosity properties of the polymer would be as follows:

Initial viscosity: 27 poise

Viscosity after 14 days - storage at 23 ° C 38 poise

EXAMPLE 6

The procedure of Example 2 was repeated except that the charge to the stainless steel vessel from 25 kg of water, 20 kg of vinyl chloride, 200 g of sodium dodecyl benzene sulfonate, 80 g lauroyl peroxide and 20 g dicetyl peroxydicarbonate consisted and the heater previously 25 kg of water, 20 kg of vinyl chloride and 200 g of sodium dodecyl benzene sulfonate contained.

The time until the pressure starts to drop during the Polarization was 8 hours. * 0 9 8 8 1V 1 1 S.

- 16 The viscosity properties of the polymer were as follows:

Initial viscosity 22 poise

Viscosity after 14 days

Store at 23 ° C- 35 poise

■ EXAMPLE 7

The procedure of Example 2 was repeated except that the charge to the stainless steel vessel was made from ', 6.25 kg water, 5 kg vinyl chloride, 50 g sodium dodecyl benzene sulfonate, 80 kg Laur.oyl peroxide and 20 g dicetyl peroxydicarbonate existed and that the reactor before 35 kg vinyl chloride, 43.5 kg water and 350 g sodium dodecyl benzene sulfonate contained.

The time to the start of the pressure drop was 9 hours. The viscosity properties of the polymer were as follows:

Initial viscosity 24 poise

Viscosity after 14 days

Storage at 23 ° C 34 poise

EXAMPLE 8

The procedure of Example 2 was repeated except that the charge to the stainless steel vessel from 12.5 kg water, 10 kg vinyl chloride, 400 g sodium dodecyl benzene sulionate, 80 g lauroyl peroxide and 20 g dicetyl peroxydicarbonate, the return time 1 min, and the reactor was previously 30 kg of vinyl chloride and

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Contained 37.5 kg of water.

The time to the start of the pressure drop was 8.5 hours.

The viscosity properties of the polymer were as follows:

Initial viscosity 17 poise

Viscosity after 14 days

Storage at 23 ° G 32 poise

EXAMPLE Q

48 kg water / water, 37> δ kg vinyl chloride, 2.4 kg vinyl acetate, 260 3 sodium dodecyl benzene sulfonate, 50 g lauroyl peroxide and 20 g of dicetyl peroxydicarbonate were placed in a stainless steel container which removes most of the atmospheric nitrogen by evacuating and purging with nitrogen \ «> Rden was. The mixture was stirred for 15 minutes to obtain a to produce a rough dispersion of the vinyl chloride in water. This mixture was then (after a return time of 5 min) through a two-stage high-performance pump homogenizer passed through, the pressure in the

2 ■

first stage 210 kg / cm and in the second stage 35 kg / cm. The homogenized mixture was stirred into a Reaction container introduced.

The reaction vessel was heated to 5 ^ ° C with stirring, the temperature was kept constant at 54 ° C. for the duration of the reaction. After 5 hours started the pressure in the reaction vessel decreased, and after further polymerization for 3 hours, the residual pressure became drained.

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The product was in the form of a polymer lat ex, the was dried by spray drying. 100 parts of the dry powder were mixed with 66 parts of dialphanyl phthalate mixed to make a paste that had the following viscosity properties:

Initial viscosity · 29 poise viscosity after 14 days

Storage at 23 ° C 150 pp

The viscosity properties are for a vinyl chloride / Vinyl acetate copolymer suitable for making pastes is acceptable.

EXAMPLE 10

Z kg of water, 18.8 kg of vinyl chloride, 2.4 kg of vinyl acetate, 280 g of sodium dodecyl benzene sulfonate, 80 g of lauroyl peroxide and 20 g of dicetyl peroxydicarbonate were placed in a stainless steel container, from which most of the the oxygen had been removed by evacuation and purging with nitrogen. The mixture was stirred for 15 minutes to produce a coarse dispersion of the vinyl chloride in water. This mixture was then passed through a two-stage high-performance

pump homogenizer (return time 4- min) through- ~ ο

out, the pressure in the first stage being 210 kg / cm

and in the second stage was 35 kg / cm. The homogenized mixture was placed in a stirred reaction vessel

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introduced, from which most of the oxygen is removed 18.8 kg of vinyl chloride and 23 kg of water had previously been introduced into the (after removal of the oxygen) had been. The polymerization was then carried out at 54 ° C. The time until the start of the pressure drop was 5 hours.

The product "was in the form of a latex and became tangy dries.

The viscosity properties of the polymer were determined in the same manner as in Example 7. They were ν; as follows:

Initial viscosity: 25 poise

Viscosity after 14 days -

Storage at 23 ° C 110 poise

OMNS.K. rrctt MPt-MS.

O. S

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Claims (1)

PATENT CLAIMS A method of making a vinyl chloride polymer, in which vinyl chloride or vinyl chloride with up to JG wt .-%, based on this, at least one additional Ethylenically unsaturated, thus copolymerizable Monomer is polymerized, characterized in that before the start of the polymerization, a mixture from monomer to be polymerized! Material and water, which is part of the total to be polymerized contains monomeric material, in the presence of an earalgator and / or a suspending agent and a monomer-soluble polymerization initiator homogenized and mixed with the remainder of the monomeric material to be used in the polymerization is, with the united parts then to. Polymerized to form the vinyl chloride polymer. Process according to claim 1, characterized in that the mixture of monomer to be polymerized ». material unl Vfesner, which part of the total to polymer monomeric .. _. sierenc.en / 1 -: - o ^ riaiP de-axed, bxc to 90 wt .- '/ a aes to "contains polymerizing monomeric material. 5- The method according to claim 2, characterized in that the mixture of material to be polymerized and water, which contains part of the total monomeric material to be polymerized, contains ξ> to 75% by weight of the total monomeric material to be polymerized. 409881/1159 Method according to claim 3, characterized in that , - "., .-,., _. . monomeric. ca ;; aas mixture of material to be polymerized and Water which is part of the total to be polymerized monoiaeren! "fetterja Is contains, 15 to 60 wt .- $ of all of the monomeric material to be polymerized. 5. Method according to one of the preceding claims, characterized in that part of the in the PoIyraerisationsreaktion to be used emulsifier or suspending agent in said mixture of to be polymerized monomeric "! material and water is incorporated, which is a part of the total to be polymerized contains monomeric material. 6. The method according to any one of the preceding claims, characterized in that the total monomer-soluble to be used in the polymerization reaction Initiator in said mixture of to be polymerized monomeric material and water is incorporated, which is part of the total to be polymerized contains monomeric material. 7 * method according to one of the preceding claims, characterized in that said mixture consists of. monomeric material to be polymerized and water, which contains part of the total monomeric material to be polymerized, part of the total contains water to be used in the polymerization reaction. 409881/1159 Method according to claim 7, characterized in that that said mixture of monomer to be polymerized Material and water which contains part of the total monomeric material to be polymerized, ois to'99 Gevi .-? o of the total in the polymerization reaction Contains water to be used. Method according to one of Claims 7 or 8, characterized characterized in that the mixture of monomeric material to be polymerized and water, which is a part. contains monomers of the entire material to be polymerized, Contains at least 10% by weight of the total water to be used in the polymerization reaction. 1C.A method according to claim 9, characterized in that that said mixture of to be polymerized monomers! Material and water which is part of the total monomeric material to be polymerized contains from 20 to 75% by weight of the total in the polymerization reaction Contains water to be used. MTBffANWS.il QtJNS. H. FINCKE, DIPt-ING. H. G. S. STAEM » 409881/1159